Within most industries, it is important that there be provided some type of seal device which prevents fluids from leaking externally from an associated bearing housing or support, and which also preventing foreign particles in the pumped fluid or environment from working themselves through the seal into the bearing.
While many sealing devices employ various types of elastomeric sealing rings, specifically lip seals, nevertheless such lip seals have a short life since they undergo rapid wear, particularly when used in environments involving fluids of a high temperature, high pressure, abrasive or corrosive characteristic. While lip seals continue to be used in many environments, nevertheless it is well documented and well known to those who are experienced in such technologies that lip seals provide only a relatively short life and hence do not provide a satisfactory solution to the sealing problem presented.
In an attempt to improve upon such problem and the solution thereto, various types of sealing ring devices have been employed. Such sealing ring devices, sometimes referred to as "bearing isolators", typically employ a pair of relatively rotatable rings (i.e. a rotor and a stator) which are respectively fixed to the rotatable shaft and stationary housing. These relatively rotatable rings have a close fitting relationship to create a complex pathway therebetween, such as a labyrinth, to hence greatly inhibit the flow or movement of fluids or contaminants in either direction therebetween. While such sealing devices have proven at least partially effective in selected use conditions, nevertheless one of the disadvantages of any such device has been the extremely complex configuration of the rings, and the consequent cost of such devices. Further, many of these nonsealing devices have been unable to prevent flow of fluids or contaminants therethrough to the desired degree, particularly due to their inability to successfully capture and expel any fluids or contaminants which gain entry into the labyrinth or pathway between the rings.
While numerous sealing devices of this general type have been developed, exemplary embodiments of such devices are illustrated by U.S. Pat. Nos. 2,524,124, 4,484,754, 3,897,072, 4,466,620, 4,572,517, 4,114,902, 4,022,479, 3,893,674 and British specification No. 2035472A.
Accordingly, the present invention relates to a sealing device of the type which employs a pair of interfitting relatively rotatable rings, namely a stator and a rotor, disposed for cooperation between a housing and a shaft rotatable relative thereto, which sealing device is believed to represent a significant improvement over prior art devices of this general type with respect to its improved level of performance, its simplicity and efficiency of manufacture, and its simplicity of installation.
In the improved sealing device of this invention, which device is known as a "bearing protector" or a bearing isolator, the stator is nonrotatably and sealingly engaged within an opening formed in the housing. A sealing relationship is achieved by use of a simple elastomeric O-ring to ensure a proper seal is maintained between the stator and the housing. Similarly, the rotor snugly surrounds and rotates with the shaft and is preferably provided with a conventional elastomeric O-ring therebetween to prevent leakage along the shaft. The stator closely externally surrounds the rotor to define a complex pathway or labyrinth therebetween which inhibits flow of liquids or contaminants in either direction therethrough. This pathway or labyrinth includes a pair of annular collecting chambers disposed in axially spaced relationship, whereby the outer chamber collects and readily discharges to the environment any contaminants which enter from the environment, and the inner chamber collects and discharges back to the reservoir any lubricant or fluid which enters into the pathway from its inner end. The configuration of these contaminant-collecting chambers ensures that the collected contaminants or fluids can be readily discharged back to their source, and at the same time the cooperation between the stator and rotor are such as to severely restrict or prevent flow of the contaminants from one collection chamber to the other.
Other objects and purposes of the invention will be apparent to persons familiar with devices of this general type upon reading the following specification and inspecting the accompanying drawings